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Using unset vs. setting a variable to empty
...t; unset var
/home/user1> echo $var
-bash: var: unbound variable
So really, it depends on how you are going to test the variable.
I will add that my preferred way of testing if it is set is:
[[ -n $var ]] # True if the length of $var is non-zero
or
[[ -z $var ]] # True if zero length
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Force page scroll position to top at page refresh in HTML
... This is the correct answer. The jQuery solution does not work in all cases.
– Harry Stevens
Dec 5 '17 at 18:52
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HTML+CSS: How to force div contents to stay in one line?
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Huge help on this, this was all that worked for me, probably spent 30 minutes on this, lol. Oddly, I'm not using any of what you mentioned, css, javascript, bootstrap, and some custom css.
– edencorbin
Dec 23 '15 a...
MySQL string replace
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Quick question, is it really needed to have the "WHERE" clause?
– John Crawford
Jul 17 '13 at 8:08
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Android - print full exception backtrace to log
...dard output and error output are directed to /dev/null by default so it is all lost. If you want to log this output then you need to follow the instructions "Viewing stdout and stderr" shown here
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How do you detect where two line segments intersect? [closed]
...f r × s = 0 and (q − p) × r ≠ 0, then the two lines are parallel and non-intersecting.
If r × s ≠ 0 and 0 ≤ t ≤ 1 and 0 ≤ u ≤ 1, the two line segments meet at the point p + t r = q + u s.
Otherwise, the two line segments are not parallel but do not intersect....
Which types can be used for Java annotation members?
...g[][]) are implicitly forbidden by the above rule.
Arrays of Class are not allowed as described in this answer.
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What does “opt” mean (as in the “opt” directory)? Is it an abbreviation? [closed]
...kages; i.e. packages that you might have paid extra money for. I don't recall seeing "/opt" on Berkeley BSD UNIX. They used "/usr/local" for stuff that you installed yourself.
But of course, the true "meaning" of the different directories has always been somewhat vague. That is arguably a good t...
How can I get a collection of keys in a JavaScript dictionary? [duplicate]
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To loop through the "dictionary" (we call it object in JavaScript), use a for in loop:
for(var key in driversCounter) {
if(driversCounter.hasOwnProperty(key)) {
// key = keys, left of the ":"
// driversCounter[key] = value, ri...
Can I force a UITableView to hide the separator between empty cells? [duplicate]
... a large enough number of cells that the UITableView cannot display them all without scrolling, no separators appear in the empty space below the cells. If I have only a few cells the empty space below them includes separators.
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